MICROBIOLOGICAL DETERMINATION OF LACTIC ACID BACTERIA FROM FERMENTED DAIRY PRODUCTS IN DIFFERENT STORAGE TIMES

Lactic acid bacteria evolution (Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus thermophilus) from two Romanian fermented dairy products (yoghurt and sana) was followed in tree stages of storage during shelf-life: in first day of storage after processing; in the middle of storage period and in the last day of storage period. An important decrease of lactic acid bacteria was observed to storage during shelf-life. This indicates a low stability of starter culture, viable germs being inhibited by other micro-organisms development (first Enterobacteriaceae then yeast and molds)

PHYSICO-CHEMICAL CHANGES IN WHOLE MILK POWDER DURING DIFFERENT STORAGE CONDITIONS

We studied the changes of total dry matter and moisture content, solubility, titrable acidity, acid degree value and scorched particle content in whole milk powder (WMP) during storage of 18 months (shelf-life). Samples were stored at room temperature and at maximum 15°C (maximum limit stipulated in Romanian standard). The samples were analyzed after obtaining and at 3, 6, 9, 12, 15 and 18 months intervals for the mentioned physico-chemical parameters. Values indicated an increase in titrable acidity and moisture content with a decrease in total dry matter and acid degree value with the storage time in whole milk powder. No significant changes were observed with solubility index under these conditions. Scorched particle content do not exceeded disc A in whole milk powder samples in neither of two different storage conditions during shelf-life